feat(binding_http): add possibility to define a custom SecurityContext

lib/src/binding_http/http_client.dart

@@ -6,9 +6,12 @@
 
 import "dart:convert";
 import "dart:io";
+import "dart:io" as io;
 
 import "package:http/http.dart";
+import "package:http/io_client.dart";
 
+import "../../binding_http.dart";
 import "../../core.dart";
 
 import "http_request_method.dart";
@@ -31,6 +34,8 @@ const _authorizationHeader = "Authorization";
 ///
 /// The use of Proxies is not supported yet, while support for the digest
 /// security scheme has been temporarily removed.
+/// Additional trusted certificates can be added via an (optional)
+/// [HttpClientConfig].
 ///
 /// [RFC 7617]: https://datatracker.ietf.org/doc/html/rfc7617
 /// [RFC 7616]: https://datatracker.ietf.org/doc/html/rfc7616
@@ -40,12 +45,30 @@ final class HttpClient extends ProtocolClient
     with DirectDiscoverer, CoreLinkFormatDiscoverer {
   /// Creates a new [HttpClient].
   HttpClient({
+    HttpClientConfig? httpClientConfig,
     AsyncClientSecurityCallback<BasicCredentials>? basicCredentialsCallback,
     AsyncClientSecurityCallback<BearerCredentials>? bearerCredentialsCallback,
   })  : _basicCredentialsCallback = basicCredentialsCallback,
-        _bearerCredentialsCallback = bearerCredentialsCallback;
+        _bearerCredentialsCallback = bearerCredentialsCallback,
+        _client =
+            IOClient(io.HttpClient(context: _createContext(httpClientConfig)));
 
-  final _client = Client();
+  static SecurityContext _createContext(HttpClientConfig? httpClientConfig) {
+    final context = SecurityContext();
+
+    final trustedCertificates = httpClientConfig?.trustedCertificates ?? [];
+
+    for (final trustedCertificate in trustedCertificates) {
+      context.setTrustedCertificatesBytes(
+        trustedCertificate.certificate,
+        password: trustedCertificate.password,
+      );
+    }
+
+    return SecurityContext();
+  }
+
+  final IOClient _client;
 
   final AsyncClientSecurityCallback<BasicCredentials>?
       _basicCredentialsCallback;

lib/src/binding_http/http_client_factory.dart

@@ -13,10 +13,14 @@ import "http_config.dart";
 final class HttpClientFactory implements ProtocolClientFactory {
   /// Creates a new [HttpClientFactory] based on an optional [HttpConfig].
   HttpClientFactory({
+    HttpClientConfig? httpClientConfig,
     AsyncClientSecurityCallback<BasicCredentials>? basicCredentialsCallback,
     AsyncClientSecurityCallback<BearerCredentials>? bearerCredentialsCallback,
   })  : _basicCredentialsCallback = basicCredentialsCallback,
-        _bearerCredentialsCallback = bearerCredentialsCallback;
+        _bearerCredentialsCallback = bearerCredentialsCallback,
+        _httpClientConfig = httpClientConfig;
+
+  final HttpClientConfig? _httpClientConfig;
 
   final AsyncClientSecurityCallback<BasicCredentials>?
       _basicCredentialsCallback;
@@ -34,6 +38,7 @@ final class HttpClientFactory implements ProtocolClientFactory {
 
   @override
   ProtocolClient createClient() => HttpClient(
+        httpClientConfig: _httpClientConfig,
         basicCredentialsCallback: _basicCredentialsCallback,
         bearerCredentialsCallback: _bearerCredentialsCallback,
       );

lib/src/binding_http/http_config.dart

@@ -4,6 +4,8 @@
 //
 // SPDX-License-Identifier: BSD-3-Clause
 
+import "package:meta/meta.dart";
+
 /// Allows for configuring the behavior of HTTP clients and servers.
 class HttpConfig {
   /// Creates a new [HttpConfig] object.
@@ -17,3 +19,19 @@ class HttpConfig {
   /// Indicates if the client or server should use HTTPS.
   bool? secure;
 }
+
+/// Configuration parameters specific to dart_wot's HTTP Client implementation.
+@immutable
+class HttpClientConfig {
+  /// Creates a new [HttpClientConfig] object.
+  const HttpClientConfig({
+    this.trustedCertificates,
+  });
+
+  /// List of trusted certificates that will be added to the security contexts
+  /// of newly created HTTP clients.
+  ///
+  /// Certificates can either use the PEM or or the PKCS12 format, the latter of
+  /// which also supports the use of an optional password.
+  final List<({List<int> certificate, String? password})>? trustedCertificates;
+}